1. Field
The subject invention is in the field or exercise apparatus which comprises a platform mounted on tracks or guides and movable on the tracks in reciprocating motion. Particularly it is in the field of such apparatus which further comprises apparatus such as springs or elastic cords to influence the motion and positioning of the platform on the tracks. Still more particularly, the invention is in the field of exercise apparatus in which the user is accommodated in a supine position.
2. Prior Art
There is profuse prior art in this field. However, the closest prior art is considered to be in three earlier U.S. patent applications by the present inventor. The earlier applications are U.S. Ser. Nos. 696,254, 786,540, and 001,192, the latter being the most pertinent. The apparatus of U.S. Ser. No. 001,192 comprises a platform, termed a shuttle, being mounted on rollers which engage the tracks of a track assembly. The shuttle is further interconnected to the track assembly with primary and secondary energy storage and release systems comprising elastic cords. The tension forces in the cords of both systems are adjustable to influence the at-rest location of the shuttle on the tracks and the forces applied to the shuttle by the cords as the shuttle moves with respect to the tracks. The primary system interconnects between the shuttle and both ends of the track assembly. The secondary energy absorption and release system is in constant engagement with the track assembly and intermittent engagement with the shuttle, the shuttle engaging the secondary system when the shuttle approaches one or both the extreme of its reciprocating motion on the tracks.
It has been determined in the course of development work on the exercise apparatus since the filing of application U.S. Ser. No. 001,192 that the cost of the apparatus could be reduced and the performance improved in terms of smoothness and quietness of the operation of the apparatus if the secondary energy absorption and release system was constantly engaged with the shuttle and intermittently engaged with the track assembly. Further, it was found that the function of the apparatus was not compromised in any way by configuring the primary energy absorption and release system so that it operates between the shuttle and one end of the track assembly rather than between the shuttle and both ends, although capability for operation between the shuttle and both ends is retained.
Therefore the primary objective of the subject invention is to provide exercise apparatus comprising a shuttle platform supported on rollers and operating on the tracks of a track assembly whereby reciprocating motion of the shuttle on the tracks is enabled, the apparatus further comprising primary and secondary energy storage and release apparatuses, the primary apparatus being constantly engaged with the shuttle and track assembly and the secondary system being constantly engaged with the shuttle and intermittently engaged with the track assembly. A further objective is that both energy storage and release systems be adjustable in terms of the at-rest position of the shuttle on the track assembly and the levels of forces in the energy storage and release systems at-rest and during operation.